Temperature sensitive switch



M. AKE'R ET AL TEMPERATURE SENSITIVE SWITCH Filed Dec. 11, 1952 IN VEN T0425,

United States Patent TEMPERATURE SENSITIVE SWITCH Morris Archer, Herbert Acker, Sidney Weitz, and Sidney J. Meistrich, Asbury Park, N. I.

Application December 11, 1952, Serial No. 325,474

4 Claims. (Cl. 200-142) This invention relates to a temperature sensitive switch and particularly to a switch to be utilized in temperature responsive alarm systems.

inthe construction and utilization of temperature alarm systems it is desirable to have a relatively simple inexpensive switch so that switches may be distributed as desired over the territory to be protected by the system without incurring a great expense.

rfhe present invention provides an insulating body having channels aiong the opposed edges thereof so that ter1ni nal plates may be mounted in the channels and a recess in the face of the body extending intermediate the channels so that conductors attached to the terminal plates may extend in spaced relation across the bottom of the recess. A bridging element of the resilient spring biased type is mounted on a cover in the recess and retained out of contact with the conductors extending thereacross by means of a fusible joint which will fuse in response to the predetermined temperature to allow the switch mem ber to be forced into contact with the conductors extending across the recess.

it is accordingly an object of the invention to provide an improved thermoresponsive switch.

It is a further object of the invention to provide a thermoresponsive switch having terminal plates recesses in the sides thereof.

it is a further object of the invention to provide a thermoswitch having a recess with spaced apart conductors mounted therein.

A further object of the invention is to provide a thermoresponsive switch having a spring biased switching element held out of contact with a pair of spaced apart conductors.

Other objects and many of the attendant advantages of the present invention will be apparent from the following detailed description taken in conjunction with the accompanying drawing in which:

Figure 1 is an exploded perspective of the thermoresponsive switch according to the invention;

Figure 2 is a vertical section through the top of the switch taken substantially on the plane indicated by the line 2 2 of Figure l;

Figure 3 is a cross-section through the switch body taken substantially on the plane indicated by the line 3 3 of Figure l;

Figure 4 is a vertical section taken substantially on the plane indicated by the line 4 4 of Figure l;

Figure 5 is a cross-section through the switch anchor taken substantially on the plane indicated by the line 5 5 of Figure 2;

Figure 6 is a sectional elevation of the switch in closed position;

Figure 7 is a transverse section taken substantially on the plane indicated by the line 7 7 of Figure 4; and,

Figure 8 is a circuit diagram showing one method of utilizing the switch according to the invention.

In the exemplary embodiment of the invention a substantially rectangular insulating body 10 is provided with 2,709,209 Fate-sited May 2li, 1955 opposed channels 12 and 14. Terminal blocks 16 and 18 are mounted in the respective channels 12 and 14. A recess 2t? is provided in the top face of the body 10 and extends downwardly between the channels 12 and 14 but in spaced insulated relation thereto. Preferably the bottom of the recess 2d is of arcuate formation as shown at 22. The terminal plates 16 and 1" are provided with lo anchor extensions 2d and 26 respectively. Anchor extensions being substantially tubular and extending into the body 19 so that they extend transversely of the recess of aperture Ztl'. The upper surfaces of the anchor members 24 and 26 are provided with flat surfaces 2S and 3G for a purpose presently to be described.

The terminal plate 16 is provided with a tubular anchor extension 32 and the terminal plate 18 is provided with an anchor tube 34. The anchor tubes 32 and 34 extend in bores 36 and 38 which extend through the body 1-, The bore terminates in spaced relation to the channel 14 and is provided with a counter-bore so that the end of the tubuiar anchor extension 32 may be peened over or headed as shown at d2 to maintain the terminal piate 16 in fixed relation in the channel 12. Likewise the bore 33 is provided with a counterbore 44 so that the end of the tubular anchor member 34 may be headed at 16 in spaced relation to the channel 12 so that the terminal block 1d is rigidly maintained in the channel 14. 'fhe anchor members 332 and 3d are provided with threaded interna*L avities so that fastening screws may be extended therein for connecting conductors Sti thereto. The conducting extensions 24 and 26 are likewise provided with internal threads so that screw fasteners 52 may be applied thereto for securing the conductors 54 thereto.

A cap ed of substantially fiat formation having downturned edges d?. and and downturned end members 66 and 68 is provided for contact with the face of the block 1b in which is located the recess 2b. T he end of the block 1t) is provided with recesses 7d and 72 adjacent the top edge thereof and the ends ed and 6d are provided with spring detents 76 and 7S for cooperation with the recesses 72 and 71:1 to retain the cap 66 firmly in position on the top surface of the body 1d. The cap 60 is provided with a substantially central aperture Sti for a purpose presently to be described. A bridging member 82 preferably constructed of resilient material is provided in arcuate formation having ends bearing against the underside of the cap 6@ having a bracket rigidly secured adjacent the central portion thereof. T he bracket 36 extends through the aperture S0 and is held in place by means of a fusible material Fusible material S8 being applied while the spring edging member e2 is in compressed relation so that the material retains the bridging member in spaced relation from the conductors 242 and 26.

A clip base 9b includes a base member 92 having a plurality of apertures for receiving mounting screws 94. End members 96 and 93 extend upwardly to receive the ends of the block 1d which is provided with recesses 1Gb and 1d?. for cooperation with detents 1M and 1% so that the body iti may be snapped into the base member 9b and frictionaily retained therein. End members 96 and 93 are provided with cut-out portions such as 10S and 116 for the passage of the conductors 50 and $4. Side members 112 and are provided for extending along the sides of the body 1b for covering the channels 12 and 1 4.

While the switch as described may be utiiizcd in many systems of alarms or indicators7 the useful system as indicated in Figure 8 where the conductors 5@ and 5d are connected to the blocks and 12 of the body As indicated, a plurality of bodies 11i may be mounted in parallel circuit relation by continuing the conductors 56 and 5d or applying new conductors 5d and 5d to the opposite ends of the terminal plates 12 and 14. Potential from any suitable source may be applied to the conductors 5? and 5d and a responsive device such as the magnetic device is connected in one of the conductors such as the con ductor 2l). A rather high impedance 3122 is connected across the open end of the circuit so that a relatively low current is drawn through the conductors 543 and and the armature i224 which cooperates the contact is mounted at one end o f the magnetic core l2@ so that the normal current flowing through the system because of the impedance 122 will be suiicient to litt the armature lid oil or" the contact 26, in the event the circuits should be broken so that no current flows there i. the t would make contact with a terminal 3.25 and energize a signal such as the bell L25. The second armature 'lsii is biased from closing contact with the contact i321, the bias being sui'licient to overcome the attraction produced by the current in the impedance However, it over tern perature should arise so that the bridging member should bridge the conductors 21- and 25, the heavy current would draw the armature 13@ into contact with the terminal X32 and energize a second signal device such as the bell 1149.

lt will thus be apparent that the present switch is of low cost, easy to apply and simple in operation so that a large number of the switches may be conveniently applied in any desired circuit and preferably in a circuit so that the circuit will constantly be tested for continity and also be continuously responsive to over-temperature in any portion of the circuit for giving an alarm or indication thereof.

From the foregoing, the construction and operati-on of the device will be readily understood and further explanation is believed to be unnecessary. However, since nu merous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction shown and described, and accordingly all suitable modifications and equivalents may be resorted to.

What is claimed as new is as follows:

l. A thermosensitive switch comprising an insulating body, said body having channels in opposed sides thereof, said body further having a cavity extending in spaced parallel relation intermediate said channels, terminals secured in said channels, a conductor secured to each ot' said terminals, said conductors extending in spaced relation in said cavity, a bridging conductor supported in said cavity, said bridging contact being biased to move into bridging relation with said conductors, fusible means restraining said bridging conductor from moving into bridging relation with said conductors, a cap removably secured on said body, said cap having an aperture therein, an anchor member on said bridging conductor, said anchor member extending into said aperture, said fusible means securing said anchor member in said aperture.

2. A thermosensitive switch comprising an insulating body, said body having channels in opposed sides thereof, said body further having a cavity extending in spaced parallel relation intermediate said channels, terminals secured in said channels, a conductor secured to each of said terminals, said conductors extending in spaced relation in said cavity, a bridging conductor supported in said cavity, said bridging conductor being biased to move into bridging relation with said conductors, fusible means restraining said bridging conductor from moving into bridging relation with said conductors, a cap removably secured on said body, said cap having an aperture therein, an anchor member on said bridging conductor, said anchor member extending into said aperture, said fusible means securing said anchor member in said aperture, said bridging conductor being an arcuate spring.

3. A thermosensitive switch comprising an insulating body, said body having channels in opposed sides thereof, said body further having a cavity extending in spaced parallel relation intermediate said channels, terminals secured in said channels, a conductor secured to each of said terminals, said conductors extending in spaced relation in said cavity, a bridging conductor supported in said cavity, said bridging conductor being biased to move into bridging relation with said conductors, fusible means restraining said bridging conductor from moving into bridging relation with said conductors, said terminals being longitudinally extending plates, anchor means on each of said terminals, said anchor means extending into and being secured in said body, the anchor means for said terminals being at opposed ends of said body.

4. A thermosensitive switch comprising an insulating body, said body having channels in opposed sides thereof, said body further having a cavity extending in spaced parailel relation intermediate said channels, terminals secured in said channels, a conductor secured to each of said terminals, said conductors extending in spaced relation in said cavity, a bridging conductor supported in said cavity, said bridging conductor being biased to move into bridging relation with said conductors, fusible means restraining said bridging conductor from moving into bridging relation with said conductors, an attaching plate resiliently receiving said body, side members on said attaching plate extending over said side channels.

References Qited in the le of this patent UNITED STATES PATENTS 1,181,705 Weber- May 2, 1916 1,868,925 Spiro et al luly 26, 1932 2,219,973 Anderton Oct. 29, 1940 

